Work scheduled for the 03 budget year includes determining compartmental distribution and directionality of LHRH flow from the hypothalamus and examining the relationship between the storage and releasable pool of LHRH in hypothalamus and in portal blood. Efforts will also continue on examination of LHRH antisera specificity namely by testing their binding affinity to various LHRH analogues. Once an antiserum is shown to nonspecifically bind to sequentially degraded LHRH fragments, it will be used in the radioimmunoassay of enzymically degraded LHRH in systemic plasma chromatographed off of TLC plates. One of the most important tasks is the testing of 2 anesthetics which were shown to be least suppressive of LH surge or LHRH release. In this study, pituitary stalk blood will be collected from steroid-primed ovariectomized rats at times predetermined by our preliminary studies as being most likely to contain the LH surge. It is hoped sufficient data can be gathered to enable us to relate the appearance of the LHRH surge with that of the LH surge. Finally, work on the biochemical characterization of endogenous LHRH or LHRH-like material in portal and systemic plasma and TRH or TRH-like substance in portal and systemic blood will be concluded.